Various portable plastic film wrapping apparatus, implements, or devices are of course known in the art. Different types or embodiments of such apparatus, implements, or devices may be found, for example, within U.S. Pat. No. 6,526,734 which issued to Huson et al. on Mar. 4, 2003, and U.S. Pat. No. 6,470,657 which issued to Huson et al. on Oct. 29, 2002, as well as within U.S. Pat. No. 6,237,307 which issued to Zentmyer et al. on May 29, 2001, U.S. Pat. No. 5,458,841 which issued to Shirrell on Oct. 17, 1995, and also U.S. Pat. No. 5,398,884 which issued to Stanford on Mar. 21, 1995. As has been disclosed within the aforenoted U.S. Pat. No. 6,237,307 which issued to Zentmyer et al., approximately fifty percent (50%) of all stretch film that is manufactured is applied to, for example, palletized loads or products by manual means. It is also known in the art that when applying such stretch film to, for example, palletized loads or products, the manner in which such stretch film is manually applied to such loads or products usually comprises either one of two methods or techniques. In accordance with a first one of such manual methods or techniques, as disclosed, for example, within the aforenoted U.S. Pat. No. 5,398,884 which issued to Stanford, the operator respectively inserts four fingers of each hand into each one of two oppositely disposed recessed portions defined within the film core end caps so as to effectively hold or grasp the film roll, and while placing his thumbs upon external surface portions of the film roll, so as to cause a predetermined amount of back tension to effectively be applied to the film whereby the film is effectively stretched as the film is being unrolled or dispensed from the film roll, the operator walks around the palletized load or product.
In accordance with a second one of such manual methods or techniques of applying a stretch film to such palletized loads or products, as disclosed, for example, within the aforenoted U.S. Pat. No. 5,458,841 which issued to Shirrell, and in lieu of directly holding or grasping the film roll, the operator holds or grasps a film roll dispensing or holding device which has a built-in tensioning mechanism. In accordance with either one of the aforenoted methods, modes, or manners in which stretch film is applied manually to the palletized products or loads, several operational drawbacks or disadvantages common to both methods or modes were apparent. Firstly, for example, the film roll, or the film roll and film roll dispensing or holding device, had to be supported by the operator personnel, and yet the film roll and the film roll dispensing or holding device are quite heavy and cumbersome. In addition, in order to fully wrap a palletized load, the operator must bend down while holding the film roll, or the film roll and film roll dispensing or holding device, in order to wrap the film around the lower extremity portions of the palletized loads or products. Such requirements upon the operator personnel have been noted to cause acute discomfort, fatigue, and stress-related injuries. In addition, the operators experience fatigue and discomfort even when the operators are wrapping the upper regions of the palletized loads or products due to the continuous need for supporting the entire weight of the film roll, or the film roll and film roll dispensing or holding device.
A need therefore existed in the art for an apparatus, and for a method of operating the same, for overcoming the various operational disadvantages or drawbacks characteristic of such known PRIOR ART systems as briefly discussed hereinbefore and as disclosed within the aforenoted patents, and this need was substantially met by means of the apparatus or system, and the method of operating the same, which has been disclosed within the aforenoted U.S. Pat. No. 6,237,307 which issued to Zentmyer et al. and which has been quite commercially successful. However, while it has been noted within the aforenoted U.S. Pat. No. 6,237,307 which issued to Zentmyer et al. that the disclosed apparatus or system is portable in that the same is mounted upon a platform which has wheels, rollers, or the like so as to render the same movable or mobile, the apparatus is nevertheless relatively large and not readily transportable so as to, in turn, not be readily or easily movable within a particular wrapping plant or facility, or even yet further, readily or easily transportable between different wrapping plants or facilities located at different production sites. Accordingly, the film wrapping apparatus or system, as disclosed within the aforenoted U.S. Pat. No. 6,470,657, which issued to Huson et al., sought to overcome the various operational disadvantages of the known PRIOR ART and in fact successfully did so. More particularly, as disclosed within the aforenoted U.S. Pat. No. 6,470,657 which issued to Huson et al., it is noted that the film wrapping apparatus or system comprises a truly portable apparatus or system which is effectively mounted upon a movable, wheeled platform which is structurally similar to a portable lawnmower.
It was subsequently determined, however, that further improvements to such an apparatus or system were deemed necessary in order to render such apparatus or system simpler in structure. For example, it is noted that in accordance with the teachings and principles embodied within the apparatus or system as disclosed within U.S. Pat. No. 6,470,657 which issued to Huson et al., a clutch drive mechanism was employed in order to control the elevational disposition of the film roll carriage along the vertical mast member. Such a clutch drive mechanism, however, is relatively complex and costly to incorporate within a portable film wrapping apparatus or system. Accordingly, such further improvements were in fact developed whereby, for example, the clutch drive mechanism could effectively be eliminated. More particularly, as disclosed within the aforenoted U.S. Pat. No. 6,526,734 which issued to Huson et al., a counterweight mechanism was operatively incorporated within the apparatus or system so as to effectively and simply control the elevational disposition of the film roll carriage. While the apparatus or system as disclosed within the aforenoted U.S. Pat. No. 6,526,734 which issued to Huson et al. has operated quite satisfactorily, it has been determined still further, however, that additional improvements might optimally be incorporated within such a system in order to render the same essentially smaller in size and easier to operate and control. For example, it is noted that as a result of physically incorporating the counterweight mechanism within the vertical mast member of the apparatus or system, the vertical height or extent of the vertical mast member is substantial.
This vertical height or dimension of the vertical mast member may sometimes present maneuverability and control problems for the operator personnel, in connection with the performance of the wrapping operations as determined by means of the repetitive steering of the portable wrapping apparatus or system around the palletized load, particularly when the counterweight mechanism is disposed within the vicinity of the upper end portion of the vertical mast member. The reason for this is that as a result of the remote disposition or location of the counterweight with respect to the base or platform of the apparatus or system, substantial moment forces or moment arms, as considered in connection with the center of gravity of the apparatus or system, are often adversely impressed upon the apparatus or system. Accordingly, the conventional apparatus or system must have a more extensive width dimension in order to provide the apparatus or system with enhanced stability. In addition, it is noted that in view of the counterweight being obviously influenced by gravitational forces, the counterweight will tend to accelerate and thereby attain different descending rates of speed per foot of vertical elevation whereby, unless the downward movements of the counterweight are precisely controlled, the film wrapping is not necessarily applied to the palletized load in a uniform manner throughout the entire vertical extent or height dimension of the palletized load. Still further, substantial shock-absorbing means must necessarily be incorporated within the lower end portion of the vertical mast member so as to effectively reduce noise, as well as potential structural damage to the apparatus or system, as a result, for example, of the counterweight sometimes impacting the bottom end portion of the vertical mast structure.
A need therefore exists in the art for a new and improved film wrapping apparatus or system, for wrapping palletized loads or products within plastic wrapping film, wherein the apparatus or system is portable, wherein the apparatus or system is relatively simple in structure, wherein the apparatus or system embodies or incorporates structure therewithin which enables both the vertical height and lateral width dimensions to be substantially reduced, and wherein the apparatus or system embodies or incorporates therewithin structure which readily enables or facilitates the manual control of the apparatus or system, the uniform wrapping of the palletized loads or products within the plastic wrapping film, and an enhanced degree of safety for operator personnel.